How Transistors Changed Electronics Forever

Sam Sattel

EDA

Battle of the Tech Titans

How TI and Bell Labs Changed Electronics Forever with the Transistor

A long time ago, in a galaxy far, far away there existed computers the size of an entire room. They’d take years to make, often costing millions in the process, with everything being powered by the mighty vacuum tube. This was the reality we lived in the 1950s, but things were poised to change when the transistor rolled around. After all, being able to place a million transistors in a square centimeter is a bit more efficient than dealing with a whole room of vacuum tubes, right?

While it’s common knowledge in the engineering community just how much transistors changed the world, what might not be as well known is the history and humanity behind the scenes. After all, the transistor didn’t just appear overnight. It took years of trial and error as we slowly transitioned from vacuum tubes to germanium transistors and finally to the silicon transistors of today. So here’s the complete story, the tale of a battle of the tech titans, and how Texas Instruments and Bell Labs forever changed the world of electronics that we know today.

It All Begins with Telephones

Our story had its beginning in 1906, and it’s here where we find a significant shift in the history of the telecommunications industry. As Alexander Graham Bell’s telephone patents began its slow creep into expiration, there was a huge surge in competition to fill the gap with something novel and new to drive the industry forward. AT&T’s solution? Create a complete transcontinental telephone service.

Some classy gentleman from AT&T present for the first transcontinental phone call. (By Irving Underhill – Bonham’s, Public Domain)

This far-reaching telephone network was made possible thanks to American inventor Lee De Forest, who created a vacuum tube device that could amplify signals on a phone line. This allowed communications to be sent across an entire continent at lightning fast speeds so long as there were switch boxes along the way.

American inventor Lee De Forest – wonder if he had any idea how far phones would progress? (Image source)

AT&T quickly gobbled up all of the patents for De Forest’s invention and set into motion their transcontinental plans, making it possible for Americans to have a phone conversation from one coast to the other. But this solution wasn’t without its problems. Vacuum tubes used way too much power, pumped out a ton of heat, and were unreliable. So it was time to find a replacement, and Bell Labs had just the idea of where to start, with some newly found semiconductor materials.

The three masterminds behind the modern transistor – Bill Shockley (left), John Bardeen (middle), and Walter Brattain (right). (Image source)

The Transistor Gets a Rough Start

Things were not all rosy for the Bell Labs trio. Shockley was reportedly a bit of a rough personality to deal with and spent most of his hours working alone at home, isolating himself from the group. But in this isolation, Shockley managed to develop his first design for a semiconductor amplifier that would serve as the foundation for the soon-to-be transistor. And while the device didn’t work out quite as planned, Shockley put Bardeen and Brattain on the case to find out why.

The two then begin an experiment with germanium to move Shockley’s idea forward, which would form the foundation of their point-contact transistor. Cut to Christmas 1945, and Bardeen has an insight, realizing that how people thought electrons behaved in crystals was completely wrong. This was the breakthrough that the team needed, and it was here that Bardeen and Brattain were able to build the first point-contact transistor on December 16, 1947.

The first point-contact transistor in all of its glory, made by John Bardeen and Walter Walter Brattain. (Image source)

This device was made from strips of gold foil on a plastic triangle, all of which got pushed down into a slab of germanium. It had three points, including the emitter, collector and the base. A positive electrical charge on the emitter would increase the conductivity of the germanium just below the collector point, which would then amplify the output current that flowed from the base. While this creation was a huge victory for the team, there was one problem – Bardeen and Brattain never told Shockley what they were doing and left him out of the picture. Woops.

Drama in the Trio

Bardeen and Brattain eventually did call Shockley to tell him about what they had discovered. And understandably, Shockley was a little more than upset, having been left out of the entire process. So what did he do? He channeled all of that anger and decided to one up Bardeen and Brattain with an invention of his own.

For the next four weeks, Shockley locked himself in a hotel room in Chicago with pen and paper in hand. And it was during this period that he would develop what is now known as the junction transistor. Shockley’s invention was profound, providing a much more durable and practical design than Bardeen and Brattain’s point-contact transistor, making it easy to manufacture.

The first junction transistor, a much more efficient and manufacturable design than the point-contact transistor. (Image source)

And so history was made, a patent was put in place, and the trio soon dissolved into a bunch of bickering children, arguing about whose name should be featured on the patent device and who would be in the publicity photographs. Outside of this drama, Bell Labs seized the moment to show off Shockley’s invention to the world on June 30, 1948.

Much to the dismay of Shockley, no one really cared. So he did what any sensible engineer would do when their invention doesn’t get the love it deserves – he took off and formed his own company, Shockley Semiconductor, and he took a bunch of talented scientists with him.

But Shockley Semiconductor was short-lived, thanks in part to Shockley’s harsh personality, and eight of his brightest employees, dubbed the Traitorous Eight, branched away. They went on to form what is now Fairchild Semiconductor and Intel, and so the semiconductor industry was officially born.

1954 – Germanium Needs a Replacement

While germanium was the go-to material for the time in creating transistors, it had both its ups and downs. When compared with the quality of silicon, it was much less reactive and had a lower melting temperature. This allowed electrons to flow through the germanium way quicker than silicon and provided a higher frequency response.

However, outside of those two advantages, the need to find a suitable replacement for germanium was clear. Current just leaked way too high, and as the temperature increased, so did the very delicate balance between the junctions in a transistor. This made it hard to control any of the free electrons.

There’s also the issue of extreme temperatures. Once Germanium heated up to 75° C, it was basically useless and a transistor would stop working. This was a definite no-go for radio manufacturers and the military, who both needed equipment that would perform reliable in extreme conditions. It was now silicon’s time to shine.

Let the Silicon Race Begin

Silicon research had been underway since the early 1950s at Bell Labs, where Gordon Teal and Ernie Buehler were growing crystals with added impurities to make the first solid-state diodes. But Teal’s stay at Bell Labs soon came to an end with his desire to return home to Texas. And so he did, landing a job at Texas Instruments Inc. as a Research Director where history would be made, again.

Gordon Teal (right) in his lab where he grew crystals that were to become the foundation for today’s silicon transistor. (Image source)

Teal had some problems with silicon though, it had way higher levels of impurities than germanium, and trying to make a successful NPN or PNP junction transistor was providing to be a heck of a challenge. So Teal and his team wrestled with this problem for over a year, and in April 1954 all of that hard work finally paid off.

With some high-purity silicon in tow from DuPont, Teal’s team was able to grow a suitable NPN transistor structure with an emitter region that enhanced the gain of a current. And when the group of scientists attached electrical contacts to the crystal on the morning of April 14th to test it out, it came to life! The first junction silicon transistor was born, and now Teal just needed to tell the masses about it.

The first silicon transistor, ready for mass production thanks to Teal and his team at Texas Instruments (Image source).

An Unassuming Introduction to the World

It’s May 10th, 1954, and a bunch of engineers gathered at the Institute of Radio Engineers (IRE) for a National Conference on Airborne Electronics. It’s pretty clear at this period in history that everyone is struggling to make silicon a viable, and manufacturable alternative to germanium, but then Gordon Teal walks on stage.

What did Teal have? Why he had a few silicon transistors sitting in his pocket! The crowd suddenly came to life, and Teal revealed to everyone that Texas Instruments had three different types of silicon transistors in production. It finally happened.

To show it was real, Teal began playing a record player amplified by germanium transistors and proceeded to dump a beaker of hot oil on the device. The music grinded to a halt. But then Teal repeated the demonstration, this time with a silicon transistor. As he dumped hot oil on the record player, the music kept playing without a hitch. And so it was official, the silicon transistor had arrived.

Teal had a rather strange and unassuming demeanor about the entire unveiling. As a Raytheon engineer raced down the lobby to a telephone telling his company that “They’ve got the silicon transistor down in Texas!”, Teal told the crowd about a simple paper published on his findings – “Some Recent Developments in Silicon and Germanium Materials and Devices.” Was this intentional on Teal’s part to downplay the whole thing? Who knows. But it is hilarious to think just how subtle the whole event was in light of its far-reaching impact.

The first integrated circuit pictured above by Jack Kilby would have never been possible without the invention of the transistor. (Image source)

With silicon transistors finally becoming viable and affordable from a manufacturing perspective, the race was on to see what we could create. As for Texas Instruments, the company became a household name as it rode the wave of success with the world’s first transistor radio.

Giving Credit Where It’s Due

So there you have it, the complete history of the transistor, from vacuum tubes to germanium, and finally silicon. The evidence of these discoveries is all around us, in our smartphones, laptops, and so many of the devices that we rely on today. And while the germanium transistor got all of the publicity of the day, we think the silicon transistor deserves just as much credit.